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Original Composite Seismic Trucks
Introduced in 1994, the original composite Seismic trucks have not been produced since 2002.
Dimensions | Construction | 2001 Parts Exchange Program | 2002 Improvements | Current Aluminum Design
Dimensions of Original Composite Truck | |
| Widths | 110mm (7.0" axle) • 135mm (8.0" axle) • 157mm (8.9" axle) |
| Weight | 13 - 14 ounces (370 - 400 grams) each – depending on hanger width, baseplate geometry and spring strength |
| Axle Height | 56mm, to accommodate a wide range of wheel sizes. Not too tall for a 50mm wheel, and with risers can take a wheel of 80mm or more. Risers have been used to increase truck height and wheel clearance for over 30 years, so don't be afraid of them. |
Technology and Construction of Original Composite Truck
- Progressive-rate dual spring system integrated with rock-steady steering geometry – for sharp, predictable turning with advanced control and stability.
- High-rebound metal coil springs with anti-buckling and tension adjustment systems – for smooth, customizable response and unparalleled power out of turns.
- Quick-Turn 45° baseplate geometry, drilled for Old School mounting pattern.
- Constructed of nylon composite and aircraft-grade metals – strong, durable and lightweight.
- Top of hanger specially contoured and reinforced with super-tough aluminum alloy – for a long life of smooth, controlled grinds.
- Smooth plane of inner face immune to hang-ups, and recessed kingpin head protected from grinds.
- Axles with oblong cross-sectional profile, molded directly into hanger, can’t ever slip and jam bearings.
- Low-friction bearing interface.
- Patented in 1993 (U.S. #5,263,725), predating cheap imitations in the off-road board market.
2001 Parts Exchange Program
Due to tolerance issues, Seismic skateboard trucks manufactured in August 2001 have pivot pins that are vulnerable to coming unwound. This is because the new Seismic factory is accustomed to conforming to European laws that require the ends of bolts on complete skateboards to be flush with the ends of nuts, to protect children from cutting themselves. So the pivot pins in the first batch were engineered to end perfectly flush with the baseplate nuts. Unfortunately, this meant that a small loosening of the pivot pins left them at risk of coming completely undone.
We deemed the potential risk of accident and injury unacceptable, and we focused significant effort to fully resolve the issue. In cooperation with most of our dealers, we implemented a program to provide free upgraded replacement parts to anyone who sends in the effected pieces. These can be identified by referring to the pictures below.
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| New baseplate on left, old baseplate on right. The four parallel recesses are smaller in new baseplate. The extra material reinforces pivot pin housing against breakage. New baseplate also molded using a compound twice as impact-resistant as old baseplate. | New baseplate nut on left, old baseplate nut on right. New nut is taller than old nut and thus grips more of pivot pin’s threads. New baseplate features taller nut, pressed more firmly into socket for easier assembly. | For more secure fastening, replacement pivot pins are longer and come with Loctite-treated threads (blue stuff). |
If you have a set of trucks from the problem batch, please contact your dealer or Seismic Skate Systems, Inc. Free replacement baseplates and pivot pins will be provided upon receipt of the old parts.
The upgraded baseplates are stronger, with solidly-fixed locknuts for easy truck reassembly. Fastening security is improved via:
- Longer pivot pins with Loctite-treated threads
- Taller baseplate locknuts for more thread grip
- Improved pivot bearing interface (less friction, better insert seating)
To retrofit your trucks with the upgraded parts, follow these instructions:
- Back out spring adjustment screws all the way, being careful not to turn them too far (this would push the spring adjustment nuts out of their sockets).
- Disassemble trucks by removing pivot pins.
- Throw out old baseplates and pivot pins.
- Reassemble using replacement baseplates and pivot pins.
2002 Construction Improvements
In 2002, we implemented the following improvements in the production of the original composite trucks:
- more secure fastening
- secondary fastening clip for total pivot pin security
- longer pivot pins with Loctite-treated threads
- taller baseplate locknuts for more thread grip
- improved pivot bearing interface (less friction, better insert seating)
- stronger baseplates with solidly-fixed locknuts for easy truck reassembly
- kingpin shoulder recessed inside baseplate for greater strength
- longer axles tips, and reshaped 110mm hangers, to accommodate all wheel types
- straighter axles, 7.95mm in diameter
- less axle threading for fuller bearing support